KAVA

In the United States, the FDA is studying the adverse reactions in 60 kava-related cases reported in this country since 1998. They include hepatitis, jaundice and liver failure. Joseph A. Levitt, the director of the Center for Food Safety and Applied Nutrition at the agency, said "Two of those cases do raise a signal for us that this is something that warrants a lot of further investigation".

I. Kava, also called kavakava, is a leafy plant that grows on Pacific islands. The processed root is the most potent part, but all of it is used. It has a tradition in a mood-altering drink among Pacific islanders, who often take it on ceremonial occasions.

In the last five years, it has become increasingly popular in the United States for alleviating anxiety and stress. Among herbal supplements, kava ranks ninth in sales. For the year ending in November, sales were more than $34 million, according to Spins, a San Francisco market research firm for the health industry, and ACNielsen.

In asking for voluntary withdrawal, the British Medicines Control Agency said it was assessing the emerging evidence, and "in the meantime in view of the potential concerns over safety, it would be prudent for the public to stop taking any product or remedy containing kavakava".

Dr. Paul Coates, director of the Office of Dietary Supplements at the National Institutes of Health, said he would not take kava. "People should be cautious", he said. "Why expose yourself to potentially harmful ingredients? The benefit is pretty much irrelevant until the risk is known. The use of dietary supplements has outstripped the science to support their use".